.TH LINEARDELTAKINS "9" "2013-07-11" "LinuxCNC Documentation" "Kinematics Component"
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.SH NAME

lineardeltakins \- Kinematics for a linear delta robot

.SH SYNOPSIS
.HP
.B loadrt lineardeltakins

.SH KINEMATICS
The kinematics model is appropriate for a rostock/kossel-style design
with three joints arranged in an equilateral triangle.  (0,0) is always
the center of the working volume.  Joint 0 is at (0,R) and subsequent
joints are 120 degrees clockwise (note that joint 0 is not at zero
radians).  The length of the arm is L.

Joints 0-2 are the linear carriages.  Axes ABC and UVW are passed
through unchanged in joints 3-8, so that e.g., A can still be used to
control an extruder.

Three pins have been provided for joints 0-2, to allow for offset trimming 
during calibration. It is suggested that these pins are only used during 
calibration to determine the proper distance between the work surface and 
the limit switches for each joint. Once the proper distance has been determined 
The pins should be set to zero and update each joints home parameters in the INI
file.
 

.SH PINS
.TP 
.B lineardeltakins.R\fR float in
Effective diameter of the platform.

R is different than the distance from the center of the table to the
center of the belt/smooth rod/extrusion that the joints ride on.  In
RepRap delta parlance, R is DELTA_RADIUS which is computed as
DELTA_SMOOTH_ROD_OFFSET-DELTA_EFFECTOR_OFFSET-DELTA_CARRIAGE_OFFSET.

.TP
.B lineardeltakins.L\fR float in
Length of the rod connecting the carriage to the effector.  In RepRap
delta parlance, L is DELTA_DIAGONAL_ROD

.TP
.B lineardeltakins.J0offs\fR float in
Offset distance applied to Joint 0 

.TP
.B lineardeltakins.J1offs\fR float in
Offset distance applied to Joint 1

.TP
.B lineardeltakins.J2offs\fR float in
Offset distance applied to Joint 2 

.SH NOTES
The R and L and joint offset values can be adjusted while LinuxCNC is running.  However,
doing so while in coordinated mode will lead to a step change in joint
position, which generally will trigger a following error if in joint
mode with machine on.

